title: Vitamin D, vitamin D binding protein, lung function and structure in COPD.
abstract: BACKGROUND
  Vitamin D and vitamin D binding protein (DBP) have been associated with COPD and FEV1. There are limited data regarding emphysema and vitamin D and DBP.
  
  
  OBJECTIVE
  This is a pilot study of a portion of the subjects in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study designed to examine the relationship between vitamin D status, DBP, FEV1 and emphysema in COPD patients.
  
  
  METHODS
  We measured serum 25(OH)D and DBP in 498 ECLIPSE subjects. Subjects were distributed amongst smoker controls, non-smoker controls, and GOLD stages 2, 3 and 4. Within each GOLD stage, the subjects were equally divided amongst high and low emphysema burden. The associations between 25(OH)D, DBP, and free vitamin D with FEV1, CT-defined emphysema, biomarkers and clinical data including CT-measured bone attenuation were assessed.
  
  
  METHODS
  25(OH)D and DBP were measured using tandem mass spectroscopy and competitive enzyme-linked immunosorbent assay, respectively,
  
  
  RESULTS
  25(OH)D was correlated with FEV1 (p = 0.01) and with severity of emphysema (p < 0.01). 25(OH)D was also associated with six-minute walk (p = 0.02), bronchodilator response (p = 0.04), and Clara cell secretory protein (CC-16) (p = 0.01). 25(OH)D levels were not associated with CT-measured bone attenuation, however DBP was associated with bone attenuation in subjects with emphysema. DBP was not associated with FEV1 or emphysema. 25(OH)D and DBP were inversely associated (p = 0.01).
  
  
  CONCLUSIONS
  This is the first study to demonstrate a relationship between emphysema and vitamin D. We also provide further evidence for a relationship between vitamin D and FEV1.
authors.affiliation: Division of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198-5300, United States.
authors.forename: Isaac
authors.initials: I
authors.lastname: Berg
authors.forename: Corrine
authors.initials: C
authors.lastname: Hanson
authors.forename: Harlan
authors.initials: H
authors.lastname: Sayles
authors.forename: Debra
authors.initials: D
authors.lastname: Romberger
authors.forename: Amy
authors.initials: A
authors.lastname: Nelson
authors.forename: Jane
authors.initials: J
authors.lastname: Meza
authors.forename: Bruce
authors.initials: B
authors.lastname: Miller
authors.forename: Emiel F M
authors.initials: EF
authors.lastname: Wouters
authors.forename: William
authors.initials: W
authors.lastname: Macnee
authors.forename: E P A
authors.initials: EP
authors.lastname: Rutten
authors.forename: Elisabeth A P M
authors.initials: EA
authors.lastname: Romme
authors.forename: Jørgen
authors.initials: J
authors.lastname: Vestbo
authors.forename: Lisa
authors.initials: L
authors.lastname: Edwards
authors.forename: Stephen
authors.initials: S
authors.lastname: Rennard
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001993:Bronchodilator Agents / Q000627:therapeutic use; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology; D011656:Pulmonary Emphysema / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D012720:Severity of Illness Index; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000503:physiopathology; D014809:Vitamin D-Binding Protein / Q000097:blood*; D016138:Walking / Q000502:physiology
chemical_list: D015415:Biomarkers; D001993:Bronchodilator Agents; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25(OH)D; Emphysema; FEV1; Free vitamin D